[daip] FRING memory requirements

Tue May 12 17:30:44 EDT 2009

Ingyin Zaw wrote:
> On Thu, 7 May 2009, Eric Greisen wrote:
> 
>> Ingyin Zaw wrote:
>>>  Hello,
>>>
>>>  I checked setapmax. It was set to 528 Mbytes. I changed it to the maximum
>>>  allowed:
>>>>  setmaxap(0)
>>>  AIPS 1: SETMAXAP: current max dynamic AP is  6144.000 Mbytes
>>>  AIPS 1: SETMAXAP: allowed range is  20 to  6144 Mbytes
>>>
>>>  I still get the same memory error as below.
>>>
>>>  The fring parameters I've set (which are not defaults) are:
>>>  calsour '2145+067'
>>>  refant 6
>>>  solint 0
>>>  aparm 3 0 0 0 2 0
>>>  dparm 3 1 1 4.1 0
>>>
>>>  (docalib -1; flagver 0; doband -1).
>>>
>>>  Thanks,
>>>  Ingyin
>>>
>>>
>>>
>>>  On Wed, 6 May 2009, Eric Greisen wrote:
>>>
>>>>  Ingyin Zaw wrote:
>>>>>   Hello,
>>>>>
>>>>>  I'm trying to run FRING with aparm(5)=2 to solve for multiband and 
>>>>>  single
>>>>>  band delays on a file with 256 channels and 8 IFs (experiment BK114A). 
>>>>>  I
>>>>>   get the following error.
>>>>>
>>>>> FRING1:   Task FRING  (release of 31DEC09) begins
>>>>> FRING1:   You are using a non-standard program
>>>>> FRING1:   Doing no flagging this time
>>>>> FRING1:   Selecting the data
>>>>> FRING1:   Dividing data by source flux densities
>>>>> FRING1:   Determining solutions
>>>>> FRING1:   Doing Least Squares fits for multi- and single-band delays
>>>>> FRING1:   Writing SN table    1
>>>>> FRING1:   Time=   0/ 02 28 14, Polarization = 1
>>>>> FRING1:   QINIT: did a GET  of      5120 Kwords, OFF   11963214967809
>>>>> FRING1:   FRNSRC: MEMORY TOO SMALL FOR SPECIFIED FFT SEARCH
>>>>> FRING1:   REDUCE DELAY AND/OR RATE WINDOW OR AVERAGE IN
>>>>> FRING1:   FREQUENCY OR USE A SHORTER SOLINT
>>>>> FRING1:   Purports to die of UNNATURAL causes
>>>>> FRING1:   rglinux9 31DEC09 TST: Cpu=      0.9  Real=      1 
>>>>>  IO=        86
>>>>>   AIPS 1: Resumes
>>>>>   AIPS 1: RETURN CODE      2 RECEIVED: STOPPING
>>>>>
>>>>>   I have set dparm 3 1 1 4.1 0. It seems strange that it fails for such 
>>>>>   a
>>>>>   small search window. It fails even when the search window is set to 
>>>>>   0.1
>>>>>   nsec and 0.1 mHz. I'm not applying any calibrations or bandpass.
>>>>>
>>>>>   I'm running 31 DEC 09, 64 bit AIPS on a machine with following
>>>>>   specifications:
>>>>>   Linux rglinux9.cfa.harvard.edu 2.6.18-128.1.1.el5 #1 SMP Mon Jan 26
>>>>>   13:58:24 EST 2009 x86_64 x86_64 x86_64 GNU/Linux
>>>>>
>>>>>   I have seen the same problem on 31 DEC 09, 32 bit AIPS as well on an
>>>>>   experiment with 512 channels and 8 IFs (BB242D).
>>>>>
>>>>>  I have made a FITS file of only the source I used for FRING for 
>>>>>  testing.
>>>>>   It's available by ftp from cfa-ftp.harvard.edu,
>>>>>   User = anonymous, password = <youremailaddress>.
>>>>>   The file is located at: incoming/lincoln/BK114A_2145.FITS
>>>>>
>>>>>  Please let me know what I can do to be able to run FRING with 
>>>>>  aparm(5)=2.
>>>>  Needless to say FRING should not do this - I note that it only asked for 
>>>>  20 Megabytes of AP memory.  It is supposed to ask for what it actually 
>>>>  needs if you allow it to do so.  Have you run SETMAXAP with a small 
>>>>  limit?  I would recommend set your max AP to 0.5 or 1 Gbyte on your 
>>>>  64-bit computer.
>>>>
>>>>  If that does not work, send me your inputs and we will fetch the file 
>>>>  and look at the problem.
>>>>
>>>>  Eric Greisen
>>>>
>>>>
>> You have asked for an FFT on the frequency axis of length 131072 or perhaps 
>> it is 524288 - I do not know the details enough to be sure.
>> AIPS now does FFTs up to 32768 and we have no plans to allow larger in the 
>> near term.  I will repair the error message which now is only about allowed 
>> size of FFTs (it used to mean what it says) and repair the limit in FRING 
>> which is currently lower than it has to be.  But that will not allow you to 
>> do what you are trying to do.  There are aips memos which describe what you 
>> should do to accomplish what you need to accomplish.
> I tried to reproduce the 131072 number and come up short. I have an 
> experiment (BK114A, 256 channels, 8 IFs) with 500 MHz total bandwidth with
> ~ 60 kHz channels which would seem, at most, to have a frequency axis of 
> length 16384. Even for 512 channels and 8 IFs, I get a frequency axis of 
> length 32768, which is within AIPS capabilities. Could you point out where 
> my calculations are different from yours.
> 
>> See the aips web page:
>>   http://www.aips.nrao.edu/
>> and read AIPS Memo 110.
>>
>> You will need to run FRING an IF at a time effectively and then solve for 
>> multi-band delay with MBDLY.
> Thanks for pointing me to the memo. It says that FRING with aparm(5)=2 is 
> better than aparm(5)=0 + MBDLY when sources are weaker. We observe at 22 
> GHz and our calibrators are relatively weaker, so we'd like the option of 
> running with aparm(5)=2, if possible.
> 
>> Eric Greisen
>>
> Thanks,
> Ingyin
> 
> _______________________________________________
> Daip mailing list
> Daip at listmgr.cv.nrao.edu
> http://listmgr.cv.nrao.edu/mailman/listinfo/daip
> 
Hi Ingyin,

I am coming into this late so I apologize if don't understand something.  How 
weak are your calibrators?  If your calibrators are weak wouldn't it be better 
to average some channels?  Why do you need 512 channels anyway? The multiband 
delay is looking at the delay between the IFs, the singleband delay is not 
calculated.

Amy